Thousands of Dutch citizens face having details of their Swiss bank accounts combed over by tax authorities despite a court ruling they should not have been disclosed.

It comes after the Netherlands authorities, stung by claims that they had not done enough to combat tax evasion, demanded information last year from UBS about Dutch citizens with accounts at the Zurich-based lender.

But a Dutch account holder this week won a Swiss legal case to block the transfer of the details.

A Swiss administrative court ruled that the request by the Netherlands for information was too general to be covered by a taxation pact between the two countries agreeing to share data.

However, it was too late for thousands of other Dutch UBS account holders who did not lodge similar appeals as information on their accounts had already been transferred to the Netherlands.

Now, the Dutch finance ministry – backed by the Swiss Federal Tax Administration – says it is still entitled to use the information it had received before the ruling. It had sought details including names and account balances.

The Swiss tax authority is appealing this week’s court decision, arguing that Switzerland’s pact with the Netherlands does in fact allow for the kind of group requests that had been made by the Dutch for the UBS accounts.

But it has now put on hold similar requests from the Netherlands that are still pending – including one asking for details on Credit Suisse account holders – until after a final ruling.

The case follows the scandal over HSBC’s Swiss banking unit after a whistleblower stole data relating to tens of thousands of accounts and passed it to French authorities.

It led to HSBC facing allegations that the unit helped wealthy clients dodge tax.

An investigation by the Financial Conduct Authority was concluded withno further action taken.

HM Revenue and Customs boss Dame Lin Homer told MPs it hadreviewed the HSBC data but that there were unlikely to be prosecutions – prompting the accusation by Conservative MP Stephen Phillips that the bank had been allowed to get away “scot free”.